Control systems for positioning elements have previously been proposed, see for example the referenced U.S. Pat. No. 3,763,745, and German Patent Disclosure Documents DE-OS Nos. 31 40 301 and 32 00 457. Control system of this type suffer from the basic problem that, if the positioning element is subject to manufacturing tolerances, it is difficult to properly control the accuracy of the value of the control current. The controlled element should, preferably, operate with low losses. While it is possible to overcome the aforementioned defects, it was heretofore necessary to use control circuits which required expensive and complex circuitry or circuit elements.